JPS58183227A - Mold for expansion molding - Google Patents

Abstract

PURPOSE:To prevent an erroneous operation on transfer molding due to defective shift, and to improve yield by studding a pin to a die receiving a molding and increasing the resistance of mold releasing in a transfer molding device. CONSTITUTION:The pin 23 having an axis parallel with a die 2 opening and closing motion axis B-B is studded at a proper position of a surface being in contact with a molding of a fixed male die 2a in a cooling die 2, and the resistance value of mold releasing of the die from the cooling fixed male die 2a is increased. The pin 24 is studded to a heating die corresponding to the cooling fixed male die 2a to which the pin 23 is studded, a heating fixed male die 1a, so that the axis is made run parallel with an opening and closing motion axis A-A in the same attitude at the same position as the cooling fixed male die 2a, the pin 23 of the cooling die is inserted unforcedly into a hole 25 for semimanufactured goods formed in the heating die 1 by the pin 24, and the resistance of mold releasing is increased without breaking the molding.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a molding tool for molding a thermoplastic resin, which ensures reliable transfer of a molded product from a heating mold to a cooling mold in a so-called transfer foam molding device. It concerns the structure of the type.

Foam molded products made from foamable thermoplastic synthetic resins such as foamed polystyrene, foamed polyethylene, and rigid foamed polyurethane have excellent heat retention and cushioning properties.

Due to its chemical stability, toughness, and low apparent specific gravity, it is widely used as a packaging material for various foodstuffs, machinery, and appliances, etc. Such a molded article is usually made by inserting all of the pre-foamed thermoplastic synthetic resin particles into a mold consisting of a male mold and a female mold, which form mold cavities by fitting each other in a manner that allows them to open and close freely. After filling and heating the mold, the resin particles are further expanded and plasticized to fuse and integrate with each other, and then the mold is cooled to harden and stabilize the resin, and the mold is opened to take out the molded product. manufactured by the method.

However, using the same mold as described above, 1!
; Completing the culm cycle (1 resin filling, heating 1 foam molding, cooling, and removal) resulted in a large loss of heat energy and time, which had the disadvantage of reducing work efficiency and increasing manufacturing costs. In order to solve this problem, a so-called transfer molding method has recently been proposed, and its use in commercial production is decreasing.

The transfer molding method uses a heating mold that is constantly heated and a cooling mold that is constantly kept cool.
After the raw resin particles are filled into the heat mold II and subjected to foam molding, and the particles are plasticized and fused and integrated, the mold L7 is opened. The molded semi-finished product is moved while being supported and fitted with the Ml+ molds of cooling J and lpJ, and the semi-finished product is transferred to the cooling mold, and the cooling male mold that has received all the semi-finished products is fitted with the cooling female mold. ? 1' This is a method of obtaining a product by cooling and solidifying the product to stabilize it. According to this method, there is no need to repeat heating and cooling for the same mold, so thermal energy is significantly saved, cycle time is greatly shortened by 1, and the molding operation can be performed subsequently, increasing productivity. This has the advantage that it greatly improves.

In such a molding method, as a means of transferring the semi-finished product from a heating movable mold to a cooling fixed mold, air is normally blown out from a heating steam hole of the movable mold to transform the semi-finished product.

An extrusion force is applied in the exit [ ] direction of the fully movable die, and in the case of the cold A1 fixed die, four vacuum suctions are performed in order to adhere the semi-finished product to this die. In this state, when the heating transfer mold is retracted, the semi-finished product remains in the cooling fixed mold, and the transfer is completed. However, depending on the shape of the semi-finished product, a transfer failure may occur, and the semi-finished product may be taken home while remaining in the heating transfer mold, or it may separate from both molds and fall. The reason for this is that when the heating movable mold and the cooling fixed mold are fitted together and the movable mold is further retracted, the semi-finished product remains in the mold that has greater mold release resistance between the mold and the semi-finished product. The above-mentioned jet and air intake actions are performed to ensure that the mold remains in the cooling fixed mold, but depending on the shape, the mold release resistance with the cooling fixed + Alternatively, vacuum leakage may easily occur, and in such cases, transfer errors are likely to occur.

The present invention was made to solve the above-mentioned problems in the transfer molding method, and its purpose is to reliably transfer semi-finished products from the heating transfer molding method to the cooling fixed molding method. The purpose is to improve work efficiency and product yield.

The apparatus of the present invention for achieving the above-mentioned objects each has l.
It consists of two sets of molding molds that can form a mold cavity with a pair of male and female molds that can be opened and closed with each other, and the first molding mold has an opening for supplying expandable thermoplastic resin particles to the mold cavity. and a means for heating the inside of the mold cavity, the second mold is a cooling mold equipped with a means for cooling the molded article in the mold cavity and a means for releasing the mold, and further A transfer molding method configured so that the male mold of one mold and the female mold of the other mold fit into each other by the movement of either one, and the molded object held in the heating mold is transferred to the cooling mold. In the apparatus, a pin having an axis parallel to the axis of opening/closing movement of the mold is installed at an appropriate location on the surface of the cooling mold that is in contact with the molded object to receive the molded object.・Development characterized by increased mold release resistance! , a mold for foam molding.

Embodiments of the apparatus of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a longitudinal cross-sectional schematic diagram showing an example of the device of the present invention,
FIGS. 2 to 4 are explanatory diagrams showing the order of operation.

In FIG. 1, a first molding die, that is, a heating mold (1), and a second molding die, that is, a cooling mold (2) are respectively male molds (
la), (2a) and female type (lb), (2b)
The male mold and the female mold are configured to be able to open and close each other freely, and a mold cavity (31, (4)) can be formed by closing the mold.Opening and closing of such molds is performed by only one mold. , for example, in the examples shown in Figures 1 to 4, the female type (1→,
(2b)? Mobile type, fixed type (la), (2a
) in the direction of the central axis. That is, the opening/closing movement axis coincides with the central axis. Each mold has behind it a mantle part (6), (7), (81° (911)) surrounded by a formwork (5).A mantle part (6) of the heating mold (1), (71 has heating medium supply port 01
), Q]l, a heating medium such as heated steam is introduced, heats the mold cavity (3), and is discharged from the heating medium outlet α2.03. On the other hand, the mantle-shaped parts (8) and (9) of the cooling type (2) have refrigerant supply ports Q41. A cooling medium such as cold water is supplied from the coolant outlet (161, (
17) is discharged from Incidentally, in many cases, the purpose of cooling is achieved only by blowing air for mold release, and the above-mentioned forced cooling is often not necessary. These mantles (6).

(71, (81, (91) uses the above-mentioned mechanism for supplying and discharging heat medium and refrigerant, as well as ejecting compressed air to the front of the mold and generating suction force from the surface of the mold to the back. As can be seen, the male type am), <z → and - type (x
b) It is preferable that the through holes drilled in (2b) are connected to a compressed air supply source or a vacuum generator through an appropriate flow path. The heating mold (11) fixed mold (1) is equipped with a group of resin particle supply devices, and its supply port a9 opens toward the mold cavity (3).

The movable mold (2b) of the cooling mold (2) has an ejector plate (2) that fits into a recess in its inner wall surface and whose surface coincides with the inner wall surface in the fitted state, which connects the mold and the mantle (9). It is fixed to the tip of a mallet C211 which is installed through the mold, and the mallet (21) is urged outward by the spring (2) and elastically supported by the formwork. Ejector plate c! 1) is a female type (
When 2b) retreats to open the mold, the free end of the punch is restrained by the stopper and protrudes forward. Here, an example has been shown in which the forward and backward movements of the ejector plate are performed mechanically, but it goes without saying that any known or conventional means using hydraulic pressure, pneumatic force, electromagnetic valves, etc. can be applied as appropriate.

The operation will be explained below with reference to FIGS. 1 to 4.

In Fig. 1, with the heating mold (1) closed, the resin particle feeder 08 is operated to supply particles of pre-foamed expandable thermoplastic synthetic resin such as expandable polystyrene, expandable polyethylene, etc. Filling is also supplied into the mold cavity (3) from the opening 9. Heat medium supply port Q (1, preferably from 110 to Qυ
If a heating medium made of heated gas such as heated steam at 120° C. is supplied, the heating medium is the mantle-shaped portion (6).

The mold is heated from (7) and a part of the mold (l→, (
The resin particles enter the mold cavity (3) through the one through hole, become plasticized, foam further, expand, fuse together and become integrated. - In the cooling mold (2), the molded body in the mold cavity (4) is connected to the cooling medium supply port Q4), a51 to the mantle part (8), (9).
It is cooled and hardened by a cooling medium, preferably cooling water, supplied to it. When heating and foaming in the heating mold (1) and cooling solidification in the cooling mold (2) are completed, the female molds (lb) and (2b) move along their opening/closing interlocking axes A-A and B, as shown in Fig. 2. - Retract along B and open the mold. As the female mold (2b) of the cooling mold (2) retreats, the ejector plate (2) is depressed by the horizontal rod 1211 i11 stopper and protrudes to extrude the product and release it from the mold. In addition, heating mold +11 is female":! 19 is opened when (l b) retreats, but at that time, which mold the foamed resin semi-finished product remains in depends on the male mold Ua) and the female mold (lb). ) The contact area between the semi-finished product and the mold wall is determined by the magnitude of the mold release resistance of the semi-finished product against , one, female type (1
The peripheral wall surface of the male type (b) is parallel to the axis A-A, while the male type (
In the case where 1a) has a tapered shape, the mold release resistance for the female mold (1→) of the semi-finished product is sufficiently greater than that for the male mold (1a), and the semi-finished product has a tapered shape. It is certain that it will remain inside.

Therefore, in order to have a difference in mold release resistance, it is possible to apply a mold release agent to only one mold, or to blow air from the mold wall in the direction in which the semi-finished product is extruded in one mold, and in the opposite direction in the other mold. Although there is a method of applying a suction force, by appropriately designing the shape of the mold cavity, that is, the shape of the female mold and the male mold, it is possible to easily generate a sufficient difference in sound for demolding resistance.

The female mold (xb) of the heating mold (1), which was opened by sniffing, moves in the direction of the arrow in Fig. 2 while supporting the semi-finished product, and opens the cooling mold (2).
) confronts the male form (2a).

The female mold (1b) then advances along the axis B--B and mates with the male mold (2a) as shown in FIG. 3, and is then retracted again to the position indicated by the dotted line in FIG. In this case, as is clear from the above explanation, the semi-finished product is naturally female (
Since the female will remain in (lb), compressed air should be placed in (lb)? Negative pressure is applied behind the male mold (2a) using a 4-pneumatic pump, etc. so that the semi-finished product is adsorbed onto the surface of the male mold (2a) at the same time as the semi-finished product is supplied and ejected from the inner wall surface to push out the semi-finished product and apply force. A female in a state where it has occurred! Ire (1b) is retracted, thus transferring the semi-finished product from the female mold (1b) to the male mold (2a).

The transferred female mold (1b) moves in the direction of the arrow in Figure 4 and confronts the male mold (la), and then both female molds (1b) and (2b) move forward and move toward the direction shown in Figure 1. As shown in the figure, each male mold (1a) is fitted with the pa 2→.

ㅅ, 1: These are the general operations of transfer molding equipment, and one of the technical problems that lowers its working efficiency and product yield is the transfer error mentioned above.

In other words, if the mold release resistance between the female and male molds is relatively small, or if compressed air leakage or parishioner leakage is likely to occur, transfer errors often occur. occurs frequently. Therefore, the key point of the present invention is that the molding action of the fixed male mold (2a) in the figure of the cooling mold (2) is 1 m! II. A bottle (having an axis parallel to the opening/closing movement axis B-B of the mold (2)) is implanted at an appropriate location on the surface in contact with the molded body,
The main feature lies in the fact that the mold release resistance value of the molded product of the cooled and fixed male mold (2→force) has been increased.Of course, depending on the mold configuration, the female mold (
In some cases, a bottle is provided in 2b) to increase the resistance value.

By the way, the bottle (23) enters into the semi-finished product that is closely fitted as the heated moving female mold (1b) moves forward, and the shrinkage of the resin that comes into contact with the periphery of the bottle causes a resistance to slipping out! As a result, the mold release resistance of the semi-finished products such as the cooled and fixed male mold (2a)'fr) increased to 71. ! This will ensure the transfer of the 8 ancient times.

pink)? ]'-If implanted only in the cooled and fixed male mold (2a), it may leave large scars on the molded body and change the appearance (or
Deterioration of function 1-? It is extremely convenient to grind several needle-shaped bottles in order to reduce the amount of water that comes out.

Also 1. Cooling fixed male type (2a) with bottle (231゛ installed)
and 71 response-r,? :, FJtl heat type 1! IIchi+J
II heat fixing klk 4V! <1a)? 6 II fixed II no, 44 (2a) in the same place and in the same posture! II Chip Close interlocking axis A-A and the axis are parallel to each other, bottle C! 41'z Since this bottle (241) allows the cooling mold bottle (23] to be inserted easily into the hole C51 of the semi-finished product molded in the 7Jrl heat mold (11), it is relatively thick. Even if the bottle of method 1 is used, it is possible to significantly increase the mold release resistance without causing local deformation or destruction of the molded product due to intrusion pressure. ) and heated bottle f
24) The effects of the device of the present invention can be sufficiently produced by making the .I method equal to the shape 1pζ. In other words, the pores (251) formed in the semi-finished product by the JJII heat M, 'J, 9) bottle (24) become narrower until the resin, which is still slightly expanding and expanding, completes foaming. This is because when the cooling type binder is inserted and the resin at the contact portion cools and solidifies, the resistance to the pin's removal increases.

For the pin (23) of the cooling fixing male mold (2a), making the diameter of at least a part of its entire length larger than the diameter of the heating mold (1→ 1!a'j is effective in order to make the action more reliable.An example of this is shown in Fig. 5.In Fig. 1, a cooling type pin θ' has a diameter that is heated along its entire length. The diameter of the bottle is uniformly larger than the diameter of the bottle example, and the bottle (
231' and (23-) each have a diameter larger than that of the pin example at a portion of the overall length.

The surface roughness of the cooled fixed male mold (2a))
Similarly, increasing the surface roughness of the pin (241) of the J11 thermomale type (1a) is also an effective method for increasing the effects of the present invention.

The dimensions of the pin (23) depend on the size and shape of the molded body, but usually the diameter is 6 mm to 20+111 mm, preferably 6 mm to 10 mm, and the length is preferably about 15 mm to 75 mm.

Historically, pins C241 of heat-fixed male molds (1 to 1) can be replaced with a material for molding.In this case, in the channel-shaped molding along the surface of the core, a cooling-fixed male mold (2Q Even if you insert a tube (binka), it will have little effect.Therefore, it is important that the hole is in the form of a tube or a gap.
In this case as well, consideration should be given to satisfying all of the above conditions regarding the relationship in shape and size between the molding cap and the pin.

The cooling stationary male mold (2a), which has received the semi-finished product from the heating movable female mold (1b) as described above, is combined with the cooling movable female mold (2b) to cool and solidify the semi-finished product to form a stable hardening molded body. After the cooling, the moving female mold (2b) is moved back, but at this time, the molded body remains in the fixed male mold (2a), ) due to the action of the pin (23), and here too, transfer mistakes occur. may occur. To prevent this, the male type (
It is also possible to eject compressed air from 2→ to push the molded product to the front, and at the same time to suck the molded product by vacuum suction on the surface of the female mold (2b), but the air system would be unnecessarily complicated. In order to avoid damage, a pin with an axis parallel to the E-B axis is installed at an appropriate position on the inner wall surface of the female mold (21), and the fixed cooling male mold (2a) and the cooling movable female mold (2a) are connected to each other. 2b) The resistance to mold release of the molded body can be completely reversed.

Smell the molded product and transfer it to the female mold (2b) to cool it securely.
The molded body is extruded and recovered as a product by the action of the ejector plate (2) which projects as the movable female mold (2b) retreats.

As described in detail below, the foam molding mold according to the present invention is very conveniently applied to the transfer molding method. In the transfer molding method, which greatly contributes to streamlining the process and improving productivity by shortening the process cycle time and saving energy, transfer mistakes in semi-finished products, which have traditionally been a major problem, can be easily solved with one device. This can be reliably solved by making improvements and modifications, by easily and arbitrarily changing the release resistance value of the semi-finished product from the mold, and by improving the work performance without impairing the appearance or performance of the product. This method greatly contributes to the use of transfer molding methods, such as improving production efficiency and increasing yield.

[Brief explanation of the drawing]

FIGS. 1 to 4 are schematic diagrams for explaining the structural aspect and operating sequence of the apparatus of the present invention. FIG. 5 is a side view showing the shape of a pin forming a main part of the device of the present invention. (11...Heating type, (2)...Cooling type. (1a), (2a)-male type, (lb), (
2b) - Female type. (31, (41... Mold cavity, (181... Resin particle supply device. 09... Resin particle supply port, (2α... Nijifuta plate. Prisoner 1. I241... Pin. A-A, B-B...Opening/closing movement axis. Patent applicant Kanebuchi Chemical Industry Co., Ltd. Figure 2 Certain 3rd eye n μ 23'

Claims (1)

[Scope of Claims] / SoJ] Zone 171 R-openable and closed'fx Consists of two sets of molding molds capable of forming a mold cavity with a male mold and a female mold, the first molding mold The mold is made of foamed thermoplastic material (+1'
The supply of resin particles [1 and 111, which is fully equipped with a means for heating the inside of the mold cavity] is a heat Ji, ν, and the second mold is mixed with a means for cooling the molded body inside the mold cavity and a mold release process. and the male mold of one mold and the female mold of the other mold somehow fit into each other by the movement of one of the molds,
In a transfer molding device configured to transfer a molded object held in a heating mold to a cooling mold, blood is applied to an appropriate place in contact with the molded object of the cooling mold that receives the manual molded object.
A mold for foam molding, characterized in that pins having three pins are installed parallel to an axis of opening and closing movement of the mold to increase resistance to releasing the molded article from the cooling mold. ! A mold for foam molding according to claim 1 (d), wherein the pins are in the form of a plurality of needles. 3 Cooling type with embedded pins and 1 heating type for λ・1,
The foam molding mold according to claim 1, wherein pins are implanted in the same positions and in the same posture as the cold JI mold. The mold for foam molding according to claim 3, wherein the pin of the cold type and the pin of the heated type have the same shape and dimensions. S The cooling type pin has a diameter along at least a portion of its entire length that is larger than the Mt diameter of the J11 heating type pin'V
4'4'+Claim 7F, the mold for foam molding according to item 3. Special feature 1 where the tapping PP-type pin is a part for meat stealing molding.
1'1 A mold for foam molding according to claim 3. 7 The pin has a diameter of 6 to 20 mm and a diameter of 15 to 20 mm.
(Claims No. 3 and 6)
The mold for foam molding according to any one of +'0. A mold for foam molding according to Patent No. 1; Item 7, wherein the pin has a diameter of 6 to 10 diameters. (g) The foam molding mold according to any one of Claims 3 to 8 of Claims 3 to 8, wherein the surface roughness of the pin of the cooling mold is made larger than that of the pin of the heating mold. 10. Adjust l1 of the heating mold so that the mold release resistance of the heating mold that is to support the molded product is greater than the mold release resistance of its counterpart heating mold.
A mold for foam molding according to any one of claims 1 to 9, which defines the shape of the ilJ cavity. //・Claims 1 to 11, wherein a bottle is installed in the cooling mold opposite to the cooling mold in which the pin is installed in a similar manner, and the mold release resistance of both cooling molds is reversed. A mold for foam molding described by several people. 12 Means y for injecting compressed gas from the inner wall surface of the mold toward the molded product through the heating mold that controls the transfer of the molded product.
4. E. The cooling mold for receiving the IJV shape is provided with means for generating negative pressure from the inner wall surface of the mold toward the back of the mold. Gold 115°